DE 199 35 873 A1 discloses a circuit arrangement for a hybrid vehicle which has a traction battery, an electric motor and an internal combustion engine which works independently thereof. The circuit arrangement, which serves on the one hand to drive the electric motor by means of the accumulator and on the other hand to charge the latter, comprises a direct voltage intermediate circuit and a first DC/AC converter which, for its part, is connected to the electric motor. In addition, a second DC/AC converter is present in the circuit arrangement, which is connected, on the one hand, to the direct voltage intermediate circuit and, on the other hand, to a generator associated with the combustion engine for charging the accumulator during braking operation of the vehicle. Furthermore, a mains-connection switching circuit is provided for charging the accumulator when the vehicle is at rest. The purpose of this circuit arrangement in the hybrid vehicle is to enable the accumulator to be charged both when the vehicle is being driven and when it is at rest.
From DE 102 26 308 A1 an electrodynamic drive device for a motor vehicle is known, which comprises a combustion engine, an electric machine that can operate as a motor/generator, an electrical energy storage device and a control and regulation system which monitors the charge condition of the electric energy storage device, for example an accumulator, and recognizes when the electrical energy storage device has reached a specifiable state of charge.
During this the electric machine is either supplied with electric power from the electrical energy storage device for motor operation or it feeds electrical energy into the storage device by operating as a generator. In addition, the motor vehicle's electrical system comprises at least one electricity consumer which, for its part, can be connected to the electrical drive device when the specified charge condition of the electrical energy storage device has been reached, particularly during generator operation, so that it consumes excess electrical energy.
The known technical solutions do not give any indication of how operating conditions, for example of a vehicle, can be managed appropriately when the conditions demand high drive-power peaks of short duration. Such operating conditions exist, for example, when accelerating for overtaking purposes or on uphill slopes, conditions which for their part entail corresponding torque increases of the drive system. The invention described below addresses this matter.
The purpose of the present invention is to provide a circuit arrangement for the control of at least one electric machine, which is suitable for also enabling operating conditions of the electric machine that entail high power-peaks of short duration. The circuit arrangement must also be designed for use in a hybrid motor vehicle.